1. Field of the Invention
This invention relates to an instrumentation for monitoring the neutron flux in a fast breeder reactor, a light-water reactor, a heavy-water reactor, a gas reactor, a fusion reactor and other types of reactors, and more particularly to a nuclear excitation laser type intra-reactor neutron flux measuring system in a nuclear reactor's instrumentation for the core and the upward section, such as a nuclear reactor control system utilizing instrumentation for monitoring the neutron flux, a monitoring system, an anomaly diagnosing system, a security system and so on, applying optical techniques.
2. Description of the Related Art
Hitherto, in order to ascertain the condition of a nuclear reactor core accurately and to improve its safety, the total density and the total flux of the neutrons within a specific area of the reactor core have been measured by determining the electric current, or by using a pulse type ionizing box to ascertain the behavior of the neutrons in the reactor based on the data obtained by measuring the total density and the total flux of the neutrons at various points in the reactor.
However, although the total density and the total flux of the neutrons at each point within a specific area in the reactor core could be measured, information regarding how the fast neutrons, the neutrons of medium speed and the thermal neutrons separately behave could not be obtained simply by distinguishing between these neutrons.